Dr. Khalsa’s Veterinary Tips July 2014

Cancer in Pets

For loving pet owners, cancer is a most feared disease. In the U.S., cancer is the primary cause of death in dogs over two years of age. That’s truly significant. Unless the mass is bulging out noticeably from the skin, most cancer grows invisibly, inside the body. Most of the time routine blood tests are normal. That’s why it’s called the silent killer.

The potential for cancer begins when carcinogens damage and alter the DNA in a cell. This damaged DNA sits and waits, like a seed on the ground waiting for water, until the conditions that promote the creation of a cancerous cell are just right. When a rogue cancer cell starts to divide, your dog has a built in mechanism to destroy the cell and force it to self-destruct. The tumor-suppressor gene p53 monitors the biochemical signals in cells that indicate that DNA mutation and division is in progress. The p53 gene instructs the cell to either halt the growth cycle or self-destruct. Your body and your pet’s bodies are set up to nip cancer in the bud, because if this fails (and there can be genetic reasons for this) the immune system will kick in and attempt to eliminate the new cancer growth. Once cancer gets a toe-hold, each type has its own special behavior.

With every passing decade the number and concentrations of carcinogens our dogs are exposed to escalates. Nowadays, exposure to toxins and carcinogens is unavoidable. While it’s impossible to avoid every carcinogen, we can certainly work to decrease our pets’ exposure to these toxins. It’s important to learn about what’s out there in the environment and how we can avoid carcinogens. One way is simply not to buy and use carcinogenic products on our dogs. Dr. Dobozy of the Environmental Protection Agency’s pesticide division states that one of the laboratory effects of fipronil in Frontline includes thyroid cancer and altered thyroid hormones. While the company creates the impression that their product does not migrate into the body, radio-labeled fibronil was found in several organs and in the fat of dogs and was also excreted in their urine and feces. Bio Spot Flea and Tick Control, Defend Exspot Treatment and Zodiac FleaTrol Spot On all contain either or both of the active ingredients Permethrin and/or Pyriproxyfen. Permethrin has been implicated as a carcinogenic insecticide causing lung cancer and liver tumors in laboratory animals. Exposure to a carcinogen typically occurs many years before the cancer appears. Often times it never escalates into a cancerous growth. Imagine how potent the carcinogens are that create cancer within several months in a laboratory setting.

According to the Center for Public Integrity who collected information through the Freedom of Information Act, the pyrethrins (naturally occurring compounds from the chrysanthemum plant) and pyrethroids (the synthetic counterpart) caused double the fatalities (1,600) in the years from 2002 to 2007 than the non-pyrethroid compounds.

The first thing we can do is find a good natural product that will keep off those pesky fleas and ticks and try to minimize the use of these toxic insecticides.   We can then expand our horizons to lawn chemicals, weed killers, herbicides and cleaning agents. Take it upon yourself to research dryer sheets and room deodorizers on the web in terms of their cancer causing ingredients. I think you’ll be very surprised. If I went into all the carcinogens that we expose ourselves and our dogs to on a daily basis this would be a very depressing article. I think we can agree that the information I have already divulged is shocking enough.

But there’s more. A growing body of research is implicating early spaying and neutering as increasing cancer risk. In a 2002 study it was established that there was an increased risk for osteosarcoma in both male and female Rottweilers sterilized before the age of one year. In another study it was shown that risk of bone cancer in sterilized large purebred dogs was twice that of dogs who were not neutered. As an aside, research indicates that the removal of the sex organs in both male and female dogs at an early age can cause growth plates to remain open.   Additionally, a study at Cornell showed that both male and female dogs neutered at an early age were more prone to hip dysplasia. Owners of female dogs are advised to spay their pups before the first heat in order to avoid mammary cancer. In my 30 years of practice I have never seen one of my patients who follows holistic care get mammary cancer, although I did get many cases of mammary cancer as their first visit. Additionally, I have never clinically found neutering to lower the risk of prostate cancer in male dogs. The College of Veterinary Medicine at Michigan State University did a small study in which they came to the same conclusion.   Urinary incontinence, hypothyroidism and a host of behavior problems have also been associated with early neutering.

While some cancers are caused by carcinogens, others are caused by viruses. It has long been known that the Feline Vaccine Associated Sarcoma is a malignant tumor associated with the FeLV vaccine and Rabies vaccine injections, occurring at the site of injection. Veterinary students are now being taught to inject these vaccines into a cat or kitten’s hind leg, so the leg can be amputated if a tumor appears. So what does this have to do with dogs? I’m not so certain that this vaccine virus will always limit itself to cat’s.

Therefore, some of the steps you might want to take to help reduce the risk of cancer in your pets are: (1) Reduce the use of flea and tick products and find natural substitutes like Ticked Off. (2) Maintain your lawn and grounds with a minimal or no toxic herbicides, insecticides and chemicals. (3) Learn more about the detergents, fabric softeners, soaps and cleansers that you use and begin to use products that do not contain carcinogens. (4) Don’t spay or neuter your dog too young. I would recommend waiting until age one year, or a year and a half. (5) Minimize vaccinations.